A Grant Under the Monbusho International Scientific Research Program "Developing studies on Horizontal Shaft Wind Turbine with Tip Vane" was carried out by the collaboration between Fluid Engineering Laboratory, Mie University in Japan and Institute for Wind Energy, Technical University of Delft, in Netherland, and between Fluid Engineering Laboratory, Mie University in Japan and The China Wind Energy Development Center from April, 1990 to March, 1991 during one year.I. The collaboration research between Mie University and T. U. DELFT solved the results as the following.(1) Wind turbine performance can be significantly influenced by tip attachments (tip vane). The power coefficient of a horizontal axis wind turbine model operating at an optimal tip speed ratio = 4 can be improved significantly by addition of small tip attachments (Mievanes).Recent results of tests carried out on the Mie university at Tsu, Japan show an measured net power coefficient 48% in case of taper blade, and 42%
… Morein case of rectangular blade. The values without tip vanes (normal wind turbine) are 42% in case of taper blade and 35% in case of rectangular blade.(2) The power augmentation is probably due to a shift of the vorticity wake in axial direction, similar to the winglet effect in airplane aero-dynamics. The phenomenon is analyzed from the velocity distributions measured by means of three hot wires, namely, three-dimensional flow patterns.(3) The power coefficient of tip vane wind turbine is affected by the shape of tip vanes. Many kinds of tip vanes were made, and tested. The relationships between good power coefficient and the shape of tip vanes are investigated.(4) The horizontal axis wind turbine occures the noise on the base of tip vortex (induced vortex on blade tip) and mechanical parts (gears or generators). The noise due to tip vortex may be diminished because the induced vortex on blade tip is reduced by the tip vane. It is very important and interesting phenomenon. The noise of tip vane turbine is going to be measured in Mie University.II. The collaboration research between Mie University and China Wind Energy Development Center teaches the tip vane wind turbine and new developed wind power generation system to the chinese wind energy researcher. It is expected to progress the development of wind energy in China by this international collaboration work.(1)チップベ-ンによって風車出力の著しい増大が達せられることが明らかになった。水平軸風車にテ-パ-翼を用いた場合、チップベ-ン無しで出力効率41%〜42%がチップベ-ンを取り付けることによって48%〜49%まで増大する。(2)チップベ-ンの形状によって風車出力効率は変化する。良い効果を示すチップベ-ン形状について一定の知見を得た。しかし、まだ全てが明らかになったわけでなく、最適な翼端形状とチップベ-ン形状の関係は、今後の研究課題として残っている。なお、これに関連して、強度が高く高効率なチップベ-ンがどのような形状を持つかは、いまだ検討中であり、今後の研究が必要である。(3)熱線風速計を用いた三次元的な翼端渦流れの測定に成功した。この測定により、これまでよく判らなかったチップベ-ンと翼端渦の関係が相当明らかになってきた。(4)チップベ-ンによって翼端渦が減少する結果、翼車の回転が滑らかになる。このため、電力の出力変動も小さく、風車翼の可変ピッチ制御も容易になる。(5)チップベ-ンによって翼端渦が減少する結果、風車周辺の空気撹乱量が減少し、騒音が軽減される。この問題については奥行が深く、騒音量測定技術も多様な為、今後さらに多くの実験的研究が必要とされる。(6)中国風力エネルギ-研究センタ-との共同研究によってチップベ-ンの風車の研究成果および実験方法をある程度中国側へ伝えることができた。しかし、中国の研究レベルは低く、この種研究への対応はあまりよくない。 Less